I'm not quite sure why they're referring to him as a CHP officer, because as far as I know Oakley PD/Contra Costa Sheriff's Dept is a totally different animal. But this is the media we're talking about, so you never know.
I drive past that intersection twice a day on my way to and from work. Unless the officer pulled out directly in front of the truck, there's no reason that the driver of the truck shouldn't have been able to see him.
Dad was on this call, so I'm hoping he'll have more information when he comes home today.